Photogrammetric restitution apparatus



Oct.20 1936. E. SANTONI v 2,057,921

PHOTOGRAMMETRIC RESTITUTION APPARATUS Filed Sept. 11, 1934 4 Sheets-Sheet 1 Evmenegildo S YH'cni 1N VE NTO Oct. 20, 1936. E, ANTON 2,057,921

PHOTOGRAMMETRIC RESTITUTION APPARATUS Filed Sept. 11, 1954 4 Sheets-Sheet 2 I I Errvxenesfldo lon] m INVENTOQ,

Oct. 20, 1936. SANTQNI 2,057,921

PHOTOGRAMMETRI C RESTITUT I ON APPARATUS Filed Sept. 11, 1934 4 Sheets-Sheet 3 Oct. 20, 1936. I E N, 2,057,921

PHOTOGRAMMETRIC RESTITUTION APPARATUS Filed Sept. 11, 1934 4 Sheets-Sheet 4 Ermenesi Ho 50 n+on5 I N YEN TO K Patented Oct. 20, 1936 PATENT OFFICE PHOTOGRAMMETRIC BESTITUTION APPABA S lirmenegildo Santoni, Florence, Italy Application September 11. 1934, Serial no. mm

. In Italy September 28, 1938 I 8C1aims. (01.88-29) v V Photogrammetric restitution apparatus is used for two or more photograms which were simultaneously taken with a multiple camera. While the object of multiple cameras is that of photographing from one and the same point in space a wider tractor country,- the object of the restitutors or rectifiers is to make possible the simultaneous. placing of several photographs which were taken with the same camera from two points, so as rapidly to pass from the restitution of one pair of corresponding photographs to that ofth'e other pairs. Once the external orientation of the photogram appertaining to one camera has been defined, the external orientations of the other pairs remain defined on the basis of the mutual angular location of the axes of the various cameras. 4 j

In the rectifiers of this class several photograms corresponding to the same viewpoint are disposed upon a single photogram-support in different planes, and relative to one another each forming angles corresponding to those formed between the focal planes of the photographic camera. Furthermore, usually a single lens similar 5 to the photographic lenses is suitably positioned relatively to the various photograms, so that by a simple angular displacement, which may or may not be combined with mirrors, or with trans-' latory movements, the lens may be successively 30 moved into the exact position of the photographic lens for each photogram.

. In such apparatus the. optical photogram observation system traverses the above-mentioned lens. Such instruments, therefore, function on the principle of Porros photogoniometer. -The device forming the subject of the present invention relates to rectifiers in which the photogram is directly observed without a photographic camera lens'orthe like. Furthermore, in my de- 4') vice, the various photograms which were taken with a multiple camera, instead oi-being in different planes, are mounted inthe same plane upon a revolving photogramcarrler, whereby thev various piates'may be successivelybrought into correspondence with the observation system and a mechanical. device conveys the .photogramcarriers and observation system roman angular position in one chamber-into anangu'lar position in another.

The observation device (binocular) while toadiustment to the various interp'upilary distances) is movable in a direction parallel to the photogram in its objective portion, whereby it maybe guided to explore the v ll'iOllS points oi mainingfixed in its ocular portion .(save for the.

the photogram by the polar movement of a guidebar, which is thus progressively operated to represent the direction of the view of the point desired. Such arrangements have been used with photograms taken in or rectified into parallel planes by means of a previous photographic or a simultaneous optical rectification. I In my device the photogram may take any angular position corresponding to the conditions under which the photographs are taken. The characteristic optico-mechanical device -provided for this pur-. pose permits also the automatic observation of the two photograms according to the nucleal planes.

The annexed drawings show an example of the practical carrying out of the invention as applied toa double and to a quadruple camera.

In these'drawings:

Fig. 1 is a schematic view-oi the photogram ob servation system showing the guide-bar attachment system and the nucleal observation device;

Fig. 2 is a front view of the instrument, partly in sectionthrough the plane 2-2 of Fig. 3;

Fig. 3 is a plan view of the instrument partly in section through the horizontal plane' H of Fig. 2;

' Fig. 4 is a side view of the instrument in section through the vertical plane l'4 oi Fig. 2;

Figs. 5, 6 and '7 show the system of substituting one photogram in another for a double-chambered camera;

Figs. 8, 9 and -10 show the supplementary motion in a quadruple camera.

According to the example shown, the instrument (see Fig. 1) is composed of two symmetrical groups, arranged along the principal axis l8--2--2 --'l which is'parallel to the plane of representation of the survey map.

.Each optical system leads the respective image towards thecentral part, where'a binocular sysdicular 8-9 let down from this point to the plane oi the photogram 1 represents, therefore, the

direction of the optical axis at the moment of the exposure. The photogram-carryinz system carries along in its angular movements amechan- 'about the said axis III-II.

Along theguide-way I2-I 3 runs a carriage carrying a spherical joint I5 through which the carriage is connected to the gudgeon pin I6. The said gudgeon pin is free to slide within the sleeve I,'I- carried by the arm I8-I9-2II (partially broken away in the drawings) which also carries the guide-bar 2 I. v

In the construction the axis of the guide-bar H is on the extension of the axis of the gudgeon pin I6. The arm II-I8-I9-20 is carried by a pivot pin 22 within the sleeve 23 of the arm 24. The arm 24 is, in turn, carried through a gudgeon pin 25 by the arm 26, which forms part of the element 3 that also carries the photogram-carrying system.

The arm 24 is rotatable by means of the gudgeon pin 25 about the axis I-8 and carries the guidebar 2| and the gudgeon'pin I6. The arm Ill-I8- I9-20, is, in turn, rotatable about the axis 22 which is perpendicular to the axis I-8. There'- fore, a Cardanic joint is produced which permits a polar movement of the axis I6-2I about the viewpoint 8, and the passage through the said point 8 of the optical path of the observation system. The guide-bar 2 I controlled by the rectifier can'iage (of known type, not represented in this figure) will produce a polar motion followed by the gudgeon pin I6 (slidable axially) which will, through the agency of the spherical joint I5 carry along with it the carriage I4 inv a sliding motion along the guide-way I 2-I 3, and in a polar motion together with the said guide-way, about the axis III-I I. Thecarriage I4 carries a lens Y21. and a straight prism 28 while the guide-way I2-I3 carries a lens 29 and a straight prism II. These lenses and prisms rotate. about the axis III-II with the guide-way I2-I3. The optical axis is so mounted that the optical axis 21-29 which parallels the guide-way I2-I3 is deflected by the prism 28 perpendicularly to the photogram I, being deflected by the prism II along the axis III-II. The straight prism III which does not participate in the rotation of the guide-wayv I2-I3 further deflects the optical axis II-I2 flat faces on which the collimation is engraved.

It will be evident that, in the plane of the glass 32 an image of a portion of the photogram I is formed, independently of the variation of the distance between the lenses 29-21 obtained during the exploration of the various points of the photogram. In order to return the image formed at '32 in the focal plane of the eye-piece 5, the lenses 33 and 34 are inserted in. the optical path. The lens 33 has a. focal ra nge corresponding to the optical path 32-8-33, while the lens 34 has a focal range corresponding to the path 34-2- 3I-5. The distance '33-2I may, therefore, be varied at will.

This is made use of to obtain the interpupilary variation between .5 and 5 In fact, the system 34-2-3I-5 is mounted upon a single support which, when shifted along the axis.8-2, may be brought nearer to or moved away from the group In Figs. 2, 3 and 4 are represented, in one constructional form, the elements indicated schematically in Fig. 1, and the other partsof the instrument to be described hereinafter. The instrument is composed of a base 4, carrying the end supports 6-6 and the central support 35. The three supports are disposed along a single horizontal axis I-I which correspond to the axis I-8-2-2 -I of Fig. 1., The base 4 (Fig.- 4) carries a system of guide-ways 36-31, parallel to the fundamental axis l-l along which runsa carriage carrying a transverse guide-way 38-39, on which runs the carriage 40. The latter carries two vertical guide-ways 4 I-42 on which runs a carriage 43 driven by a screw 44. The carriage 43 (see Fig. 3 in which, for the sake of simplicity, the details 36-31-38-39-40 are omitted) carries two sleeves 45-45 within which are slidable the arms 46-46 for establishing the base component X, while the components Y and Z are established by means of the slides 41-41 carrying the Cardanic connections of the sleeves 48-48 which run along the guide-bar 2I-2I The details from 36-to 48 relating to the carriages, represent an ordinary form of execution.

The central supports 35-35 (Fig. 2) are hollow cylinders, and the end pins I02I02 serve as supports for the parts 3' and 3 which are rotatis connected at right angles with the external hollow cylinder 50 The cylinder 50 constitutes a system together with the arm 5I the ring 52 and the arm 53 which latter is supported by, the conically pointed screw 55 by the lower appendage of the arm 3 The entire system 49 -50 -5I -52 -53 is exploration system, whereby the photogram is caused to assume the inclination corresponding to the conditions of the exposure. To this end, the ring.52 supports, through the counter-ring 56 the ring 51 which in turn, supports through the arm 58 the frame 59 carrying the photogram I. Due to the freedom of rotation of the ring 51 relatively to 52 -56 the photogram may assume the requisite orientation. Within the used to indicate the value corresponding to the focal range attained.

The rotation of the part 3 (see Figs. 1 and 2) about the fundamental axis would cause a detrimental rotation of the image in the eye-piece.

To prevent this, the Amici prism 30 is interposed in the optical path, and is mounted in the usual manner on a rotatable ring (not represented in the figure) which carries the planet-wheel 85 -48 -81 of a differential, one of whose bevel wheels 86 is fixed, while the other 81 follows the movement of the part 3 In the example shown, the bevel wheel 86 may, in order to effect slight initial rectifications, also be caused to perform slight angular movements through the medium of the tail-piece 68 actuated by a screw 69. As the rotation about the axis 54 55 of the system carried by the tube 49 would also occasion a detrimental rotation [of the image, the bevel wheel 61 is not actually fixed to said functions, performs a third important function, consisting in the returning of the images observed on the two photograms to their mutual orientation, in agreement with the corresponding nucleal plane. To this end, the bevel wheel 10 is not fixed to the tube 49 butris free to rotate, controlled by the pinion 12 which causes also the rotation in an opposite direction, of the sleeve 13 upon which is mounted the glass displaying the collimation mark 32 The axis of the pinion I2 traverses the tube 49 and is carried by this tube. An opening in the part 3 opens the passage towards the outside of this axis in order to connect with it a lever 14 (see Fig. l likewise) The width of the said opening permits also a connecting-rod 15 endingin a small ball I00 which is lodged within the groove cut in the sector 18 connected to the arm 24. The centre of the sector 16 corresponds to the point 8. The travel of the small ball I00 along the sector is brought about by the rotation of tl1e,tube 48 and, hence, of the photogram-carrying system. The axis 11 of the pinion I2 is maintained parallel to the axis |0|| and thus, perpendicular to the photogram. In the particular case in which the optical axis 8-9 is perpendicular to the fundamental axis the ball I00 will be situated on the said axis In this case, the rotation is represented by the cathet of the arm 24, and hence of the sector 16, fails, due to the polar motion of the guide-bar 2|, to give rise to any movement of the connecting rod 14. In such a case the nucleal planes intersect the photogram through so many parallel straight lines, whereby no correction of the orientation is called for.

In the more general case, the optical axis 8-9 will form with the fundamental axis a certain angle a differing by 90, as is indicated in Fig. l.'

Fig. 1 represents the particular case when the axis of the guide-bar 2| coincides with the optical axis. This indicates that collimation is effected at the main point 8 of the photogram. For the sake of simplicity in the drawings, the distance between the spherical joint I 5 and the photogram 1 is not taken into account, at present, the photogram being assumed to be at the focal distance from 8. The nucleal plane, 1. e. that passing through |-89, intersectsxthe photogram along the line |--9 which represents the .particular place for the points which are to appear in the eye-piece, following, a line parallel to that connecting the pupils of the eyes of the observer, for the purpose of ensuring-the best stereoscopic efiect. Should this not be initially obtained, due to defective adjustment of the 1n-- strument, it might easily be brought about-as already described-through the rectification, by hand, of the screw-knob 89. In the passage from the observation of the point 8 to the observation of another generic point IN the line extending through the nucleal plane, however, becomes |-|0|, whereby rotation of-the image through an angle e becomes necessary. The value of 6 18 -19 of the triangle spherical at 18-1 0, a rectangle at I8. The other cathetus 18-80 is equal to 90-, a being the angle formed between the axes |8 and 8-9, while the angle at 80 (5) represents the dihedron through which the arm 24 will have rotated, and therefore the sector 18, in order to bring the collimation from the point 9 to the point II. The ball I00 is initially along the sector 16 in a position corresponding to the angle 90--; as represented in Fig. 1. In passing from the point 8 to the point |0|, the sector 18, rotating through the angle 3, causes the ball I00 to move, whereby the lever 14 is rotated atv an angle, e. The length of the connecting rod 14 is equal to the radius of the sector 16. The disorientation to be corrected by the device precedes the mark 32. Therefore, the mere rotation of the image forming in correspondence with the mark, while it would improve the vision of the landscape, would disorientate the mark. In order to prevent this,

the bevel wheel 12, while transmitting the requisite correction to the Amici prism, causes the mark 32 to rotate in the reverse direction by the same angle, thus definitely obtaining the.

For the interpupilary adjustment of the eyepieces 5-5 the approximation and the retrocession of the prisms 2---2 together with the lenses 34-34 (Fig. 2) is eflected through the rotation of the shaft 8|, which carries two oppositelyscrew-threaded parts over which the sleeves are inserted. Each of the sleeves carries a prism 2 and 2 or a lens 84 or 84 Similarly, 76

' sories thereof, while the groupsacting in unison I approximation or the retrocession of the lower prisms 3I-3I as well as of the eye-piece-carrying tubes 03-83 By means of a system of gears M and 82 interconnected by a chain the movement of the shaft 82 is also transmitted to the shaft 8|.

The elements controlling the inclination and .the orientation corresponding to the exposure are constituted as follows:- (Figs. 2 and 3) A sector 84 concentric with the viewpoint 8, is integral with the pin I02 and is provided with an appendage 85 actuated by a micrometric screw 88 with an antagonistic spring (see also the details in section of the right-hand symmetrical group). Part 81 is shiftable along the sector 84, by means of the tangential screw 89. The part 81 carries a sector 88 concentric with-the point 8 and located in a plane normal to that of the sector 84. Part 9| may be shifted along the sector 88 by means of the tangential screw 90. The part 9| carries the pin 92 whose axis, in the position indicated in the figure, coincides with the fundamental axis of the instrument I-I 'I'hepart 95 is an appendage of the ring 51 connected to the photogram-carrier (see also Figs; 6, 8, 9 and 10) In the particular position of the various organs represented in Figs. 2, 3 and 4, the axis of the pin 92 coincides with the axis l-I Under such conditions, the turning of the tangential screw 94 causes the rotation about the axis I-I of the group of parts 93-95-98-51- I-3 and their accessories. The said parts rotate in unison to the same extent. If, owing to the shifting of the parts 81 and 9| along the respective slides 84-88, the axis 92 happens to be in some other position, by'the manipulation of the said tangential screw 94 parts 93-95-51 and their accessories are rotated only about the said axis 92. The system composed of the parts 3-50-5I and of their accessories, being combined with the axes of rotation I-I and 50-55, follows the motion of the ring 51 according to the relative resultants of motion of the said axes. Always starting from the particular position represented in Figs. 2, 3 and 4, the manipulation of the tangential screw 90 would cause the rotation of the parts'9I-93-98-51-58-59 about the axis 9-8 corresponding to the optical axis. That is to say, the photogram would be rotated in its own plane about the main point. The turning of the tangential screw 89 would cause the rotation of the ensemble of parts 81-9I-93- 98-51-50-53 and of the accessories thereof, about the axis 54-55. A movement of convergencewould be obtained. When the axis 92 is no longer coincident with the axis I-I the tuming of each of the tangential screws 88 produces a movement corresponding to that of the respective slide 81 as far as the ring'51, and the acceswith the axes I-I and 50-53, perform the movements in accordance with the said axes, similarly to what occurs in connection with'the screw 90. Finally, the turning of the micrometric Upon manipulation of the tangential screws 89-90, the

the rotation of. the shaft 82 brings about thescrew 88 rotates the whole group comprising tangential screw, sectors, parts 3, etc., about the axis I-I, independently of the position of the.

axis 92. A similar arrangement of elements for establishing the external orientation of the photogram is shown in Figs. 5, 6, 7, 8, 9, 10. Fig. 5 is a schematical representation of a double chambered photographic camera. The optical axes 98-9 and 99-91 of the two chambers form a certain gle Let us assume in the chamber a material axis 91-92, normal to the planes 98-91-99. /Let us also assume that the rectifier establishes "the external orientation of the photographic camera by varying axis 91-92 or by the inclination and the orientation corresponding to the exposure being imparted to the said axis, relatively to the plane of representation of the instrument. All this is indicated by means of the axis 92-91 in Fig. 6.

The photogram-carrying system is constituted by a ring 51 carried by the sector 96, carried, in turn, by the axis 92.

tuated by a tangential screw 94) and with a sliding pin 95 that may be inserted into the opening 99 in the sector. After the external orientation has ben imparted to the axis 92-91, the tangential screw 94 may be rotated to impart to the photogram the external orientation corresponding to the chamber II. When it is desired to pass from the chamber 11 to the chamber I, the pin 95 is disengaged from the opening 99 of the sector 96, causing the photogram-carrying system to rotate about the axis 92-91 until the pin 95 enters the aperture 98 provided in the said sector 96. This happens when the angle formed between the lines connecting the axis 92-91 with the said openings is equal to the angle s formed between the axes of the two photographic chambers.

. The parts described in Fig. 6 correspond with those indicated by like numerals in Figs. 2, 3

and 4.

Simultaneously with the changing of position of the photograms, it is necessary to effect the replacement of the photogram of chamber 11 by that of chamber I. This is shown in Fig. 7. The ring 51 carries a pivot or pin I03 which serves as a support for the frame I04 upon which are the frame will carry an equal number of plateswith respective stop-notches for the stop-tooth I05.

A more genericapplication may be given to the instrument, viz. one corresponding to a. multiple photographic camera with groups or chambers disposed in several planes, for instance, a quadruple camera, whose axes are disposed two by two in two planes forming an angle 4: (see Figs. 8, 9 and 10) In order to efiect the exchange between one couple and another it is sufficient to impart to the plate 95 an angular motion 4: relatively to the axis of the pin 92. This is effected by giving to the plate 96 the shape of a. spherical calotte in which is cut a groove provided at either .end with two apertures I08-I01'forming, with 7 the centre 91, the angle 95. There are provided in the same plate the apertures III-.-III--IV whereof I and 11 "form, with the aperture I01, the angle corresponding to that formed between a couple of chambers I-II. Similarly, the aperture-III and IV form, with I06, an angle, whose value is connectedwith that of the other two chambers III and IV.

The extremity of the pin 92 remains fitted into the groove I 00-I01 while .a concentric pin I08 that is shiftable by means of "the external stud I09 may be brought into engagement with one or the other of the apertures I00I01.

While in Figs. 8 and 10 the line connecting the aperture -I01 with the centre 91 is. parallel to the plane of the ring,.51, in practice it is the bisector of the angle that should lie parallel to the said plane. The angle formed on the plate 06 does not' correspond to the real angle s formed between the axes of the two. chambers I and II, but rather to the projection thereof in a plane normal to the connecting line I01-91. This ap plies also to the other two chambers.

The rotatable photogram-carrier I04 (Fig. 7) is adapted to contain a number of plates corresponding to' the number-of apertures in the plate 90. The groove I06I01 may carry a number of apertures greater than two, and to each of these The rectification in connection with the total number of chambers of a multiple camera by means of the manipulation of the knobs 95 and I00 applies solely to the case in which'the total field of an exposure viz. that corresponding to the I sum of the fields of each chamber, totally overlaps that of the successive exposure. Let us now assume a quadruple camera in which only the overlapping of the field of the chamber III and IV of an-exposure and of the chambers I andII of carrier for the chambers the successive exposure occurs. Let it be asmined, for instance; that the photograms III and IV have been mounted in the left-hand group of the rectifier, which photograms have a field in common with the photograms I and II of the successiveexposure, mounted in the right-hand group.- In such case, the passage in the left-handv group, through the shifting of the pin I08 from the position of the chambers III and IV to the position corresponding to the cameras I and It,

cannot give rise to rectification as regards the said chambers, unless recourse be had to a reversal of the images between the eye-pieces 55 by means of well-known arrangements. however, possible in the rectifier forming the object of the present invention, to utilize the positions assumed by th left-handphotogramand II by transferrin the angular values relative to such positions to the right-hand group, together with the photogram-carrier I04 containing the plates I and II.

This is eflected as followsz-After having, through a manipulation of the pins I00 and 05, conveyed the left-hand photogram-carrier to the position of chamber I, the spirit level H0 is mounted upon the ring 51, which level may be rotated by-means of the knob I'Il until the air bubble is brought'to the centre. Furthermore, the part 3 (Fig. 2) carries, in the-direction of the central support 35, a graduated arc II2, upon which a vernier, fixed to the central box II3, permits the reading of an angle corresponding It is,-

to the position assumed by the part 3. Similarly,

the part 49 carries a graduated arc II4, upon. which a vernier fixed to the part 3 permits the reading of an angle corresponding to the position assumed by the part 49 (and consequently by the entire system rotatable therewith) relatively to the part 3 (see the corresponding details in the right-hand group, Fig. 2).

The level I I0 may be removed from the left hand group and mounted in the right-hand group together with the' photogram-carrier.

By actuating the knobs 09 -00 -94 it will be possible to impose upon the two right-hand scales H2 and H4 the values read off on the left, and to impart to the ring'51 sucha position that the bubble II0,- "having been shifted thereto, may again become centered. Thus, the

right-hand photogram-carrying group assumes a position corresponding to that of the left-hand group for the plates I.

The ,group pertaining to the spirit level II 0 may be simply fixed to the plate-carrier plates I04. In case it should be desired to shiftthe position of several chambers, said plate will carry a corresponding number of levels.

In order to impart to the photogram-carriergroup the angular rotation corresponding to the exposure, the slides are moved by the knobs 899094. The sector 84 may therefore he in a plane common to the sector 84 and such plane may be normal to the axis of the guideway 42 (Figs. 3 and 4). After the reciprocal optical orientation'of the two photograms has been effected through turning (in opposite directions) the knobs 89-49 it is possible to rotate the optical model in the plane normal to the guideway 42. By turning the knobs 00-86 in the same direction, the optical model will be rotated relatively to the axis II The knobs 00-80 '8980 may be provided with a graduation permitting the measurement of the angular displacements. In connection with these rotations suitable variations are required to be made in the base components w-zF-z.

It is to be understood that the drawings constitute exemplifications which may be varied without 'departing from the scope of the invention defined in the claims.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I

' declare that what I claim is:

1. 'In an apparatus of the class described composed of two symmetrical optical parts each of which has a common main axis anda secondary axis normal thereto, a photogram-carrying system, means for rotating'it about a point representing the prospective viewpoint into the angular position corresponding to the exposure; an optical observation system comprising ,optical means having an object lens and prism mounted upon a carriage, means for displacing the carriage in a plane parallel to the photogram, said last-mentioned means including a guide bar pivoted at the viewpoint.

2. An apparatus according to claim I, and in which means are provided for rotating the photogram-carrying and the optical exploration system about the main and the secondary axes, said axes intersecting at the viewpoint, observation eyepieces located near the center of the instrument between the two symmetrical halves of same, and means for conducting the opticalpath along the aforesaid main and secondary axes towards the said eyepieces with a view to permitting binocular vision.

3. In an apparatus according to claim 1, an Amici prism in the optical path, means including.- two bevel gears between the main and the secondary axes and a difierential gearing for rotating the said prism at one-half of the angular movements of the photogram-carrying system about the main and the secondary axes, whereby the image is'maintained oriented.

' 4. In an apparatus according to claim 1, an Amici prism in the optical path, means for rotating the said prism about the main axis at one-half of the angular movement or the photogram-carrying system, an arm carrying the guide bar, means for rotating the said am about the main and the secondary axes, a grooved sector ing a main optical axis and a secondary optical axis normal thereto, a photogram-carrying system, means for turning it about a point representing the prospective viewpoint to give it the angular position corresponding to the exposure of the photogram, an optical photogram exploration system comprising a carriage, means for displacing the carriage in a plane parallel to the the said levers.

photogram and'including a guide bar, means to mount said bar to pivot at the viewpoint, means for imposing the movements of inclination and orientation of the photogram upon the photogram-carrying system, the last-mentioned means including a system of slides and of sectors concentric with the prospective viewpoint for shift- 1 ing said slides, a pin actuated by the said sectors. whose (extended) geometrical axis passes through the viewpoint, and gearing carried by the said pin for rotating the photogram -carry ing system by an angle corresponding to that formed between the optical axes of a multiple camera, having the said axes lyingin one and the same plane, whichis normal to the axis of the said pin.

6. An apparatus according to claim 5, characterized by an axially slidable gudgeon pin to shift the turning point of the photogram-carrying system relatively to said pin.

'7. An apparatus according to claim 5, in which a plurality of photograms are carried in the same plane by the photogram-carrying system through a revolving means, and stops for holding said carrying system.

8. An apparatus according to claim 5, charac-- terized by levers for rotating the optical systems' about the main axis, and graduated knobs for effecting and measuring the said rotation,

all the other angular movements of the photogram carriers being eifected independently of ERMENEGILDO SANTONI. 

